


Mandatory, Part 3.

by n0xx



Series: Mandatory [3]
Category: Harry - Fandom, Harry Potter - J. K. Rowling
Genre: Anal Sex, Angst and Fluff and Smut, Cheating, Dinner, Drama & Romance, F/M, Hogwarts Professors, Infidelity, Kissing, Oral Sex, Power Play, Resolved Sexual Tension, Roleplay, Romance, Rough Oral Sex, Rough Sex, Roughness, Sexual Inexperience, Sexual Roleplay, Sexual Tension, Shameless Smut, Smut, Teacher/Student Roleplay, Teaching, Vaginal Fingering, Vaginal Sex
Language: English
Status: Completed
Published: 2020-10-11
Updated: 2020-10-12
Packaged: 2021-03-08 03:40:53
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 3,875
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26949133
Author URL: https://archiveofourown.org/users/n0xx/pseuds/n0xx
Summary: Lily and Severus have their time at Hogwarts. Lily is in charge, again.
Relationships: Lily Evans Potter/Severus Snape
Series: Mandatory [3]
Series URL: https://archiveofourown.org/series/1885567
Comments: 60
Kudos: 45





	1. Boundaries

Boundaries. Rules. Severus' mind flitted nervously between possible rules for the situation he was about to enter into. He was allowed to have rules, right? 

His chambers at Hogwarts had very recently been obsessively organized and cleaned in preparation for that evening. Becsuse they were more like a small apartment than just a bedroom, he'd also opted to have dinner ready for them. It sat covered on a small table that he'd outfitted with a candle and a small flower in a vase. This made him feel a little less like he was just a booty call. Ugh, was he?

Frank Sinatra's voice flowed smoothly through the room. 

_And I've got no defense for it, the heat is too intense for it, what good would common sense for it do?_

7 o'clock came too quickly and too slowly at all once. It found him standing near his fireplace, nervously awaiting Lily's arrival. He paced a little then alternated between leaning against the couch and standing with his arms folded, effectively wrinkling his slightly unbuttoned white dress shirt. He also wore dark slacks with matching brown belt and shoes. His dark mane was brushed almost obsessively and fell smoothly onto his shoulders. 

But by the time 7:05 rolled around with no sign of Lily, he had sufficiently messed his hair up by repeatedly running his hands through it. 

When the fireplace burst into green flame at 7:09, Severus could have cried. He tried desperately to collect himself as Lily appeared, sporting a black cocktail dress that fell just above her knees. He swallowed hard, admiring her as she stepped out. A sheer panel at upper chest of the dress gave him a window to her collarbone and cleavage. The wizard's mouth went dry when he noticed that she also wore strappy black heels to match. "Hey, Sev."

"L-lily, Hi." Severus hesitantly approached her and offered to take her bag. 

When she noticed his trepidation, Lily reached up to stroke the man's cheek. "I'm sorry I'm late. I didn't mean to worry you, it's just that Ja-"

"It's alright," Severus said abruptly, silencing her. He'd been soaking up her tender (new to him) touch when she'd almost said her husband's name. That wouldn't work. That could ruin everything. Well, now was as good a time as any to mention his rules. She was close enough to the exit that she could leave if she disagreed. "We need to talk."

Lily looked at him curiously and dropped her hand to her side, but said nothing. When she nodded, her wavy auburn locks slid softly over her shoulders. The scent of her perfume filled Severus' nostrils. God, what _was_ that smell? He wanted to bathe in it. His cock twitched in response. 

"If you want.. me," Severus said awkwardly, "...any part of me.. then you can't talk about James here." He sighed and ran a hand through his hair again. "He can't exist here." _I just couldn't handle it._ There was a heavy moment of silence as they stared at each other. "But then you can have whatever you want. Anything. I'll do it." 

"Anything?" Lily rose an eyebrow. 

_"Anything,"_ Severus breathed, the word sounding like a desperate plea and a dark promise at the same time.

She said nothing else about the matter, simply pulled her wedding band off her slender ring finger, popped it in her clutch, and handed the bag to Severus. "What's for dinner, Sev?"


	2. Dinner

"D-dinner, um.." Severus tried to steady himself as he walked over the dining table with Lily and pulled out a chair for her, ignoring the effect her dress had on him. Or trying to. The way it clung to her hips made his mouth water. After he pushed her chair in, he reached for a chilled bottle of wine he'd acquired. "Salmon," he said lamely, pouring her a glass of pinot noir before he took the dome off of her plate. Of course it wasn't _just_ salmon. It was pan-seared salmon with a lemon butter cream sauce, asparagus, and herb-roasted potatoes. He'd taken special care to find the recipes and request that the Hogwarts house elves make it. Hell, he had even ordered a special dessert. But as he took his seat across from Lily, he realized he wasn't hungry for food.

"This looks incredible, Sev," the redhead told him sweetly, placing her napkin delicately on her lap. A reflection of the flickering candle on the table shined in her emerald eyes. 

_When the world is cold, I will feel a glow just thinking of you, and the way you look tonight..._

"I'm glad you think so." The wizard managed to regain his composure enough to set his own napkin on his lap and uncover his dish. _Breathe, Severus, you're just eating dinner._ "So, tell me about your work," he began, stifling a smirk as he considered his own experience at the hands of Lily Evans, Healer. 

With that, they fell easily into conversation. It was as if no time had passed between the point in their lives when they'd been best friends, and now. They laughed, spoke freely and comfortably about their lives since then, and Severus felt surprisingly at peace. The name James Potter and the word "husband" was never uttered. Not even once. 

There were points in their conversation where Lily brushed her hair over her shoulder or seemed to be staring deeply at Severus.. those moments made his heart skip a beat and his pants tighten. Was this all she wanted from him? Dinner and conversation? He almost didn't mind; it made him feel like she had actually missed _him_ and wasn't just looking for some strange sexual outlet with the least experienced lover on the planet. 

Once they'd both finished most of their meal, Severus stood to clear the plates. He had just flicked his wand at the last dish when Lily softly wiped her mouth, then stood. "Thank you for dinner, Severus."

"Certainly."

The fiery haired witch circled the table so that she was standing in front of him, then put a perfectly manicured hand on his chest, and pushed him back a bit. Severus found himself complying immediately and sat down on the edge of the dining table, his breath leaving him suddenly. "I h-have dessert," he murmured, glancing from her hand up to her face, which looked mischievous and pleased. Suddenly, he wasn't so sure she'd be interested in a fruit tart. "Or we can... um, skip it."

"Let's, if you don't mind," Lily purred. She nudged her way between his legs so her front was pressed up against him and then placed a hand on the side of his neck, pulling his face down to hers for a kiss. It was soft, loving. Sweet. Then she found his lower lip and sucked it hard, nipping at it a bit as she did so. 

"I don't mind," Severus panted when he was released from the kiss. His dark eyes searched hers curiously. He felt flushed and cornered. "Anything you want, you know that."

"I love to hear you say those words, Professor Snape."

The wizard rose an eyebrow at the title. 

"I know you're usually the teacher," Lily continued, "But I was thinking I could educate you a bit this evening." With that, she traced a finger down the front of his shirt, smirking a little when it finally landed on his belt. 

"A-and what do you plan to educate me on, Miss Evans?"

"How to please me," she told him confidently, gripping his belt buckle and pulling him to her. Her free hand found his erection, which was straining against the fabric of his slacks, and gripped it firmly. "How to make love to me. Is that a topic that interests you?"


	3. Good Grades

"I believe you have your answer," Severus said dryly, nodding down at his cock, which Lily seemed to have claimed. 

"Lovely," Lily told him sweetly, giving it a firm squeeze before releasing him. She stepped gracefully away from him and glanced around the room; it looked a bit like a very large studio, complete with a plush seating area by the fireplace, a king sized bed with dresser and nightstands, the dining table, and what appeared to be a private bathroom down the hallway. "The rules of my classroom are simple," she said, appearing to plan out her next move. "You'll follow my instructions exactly. No improvisation unless I say so." When she turned to face him again, she smirked. "I assume you want good marks in this course."

"I'm committed to achieving First Class Honours, Professor Evans."


	4. Rewards

"But what if I disappoint you? If I make a mistake?" Severus asked curiously, raising an eyebrow at Lily. Would he be punished?

"You won't." Lily turned back towards him and grabbed the center of his shirt in her hand, pulling him upright again. "You couldn't," she said honestly, looking him in the eyes. For a brief moment, their playful banter had been paused. "You love me."

The statement hung in the air, painfully true, before Severus managed a whispered _"Yes."_

A sad, soft smile crossed Lily's face briefly. Then she turned around, exposing her back to him, and instructed him. "Undress me." She reached up to pull her hair into her hands and slide it over one shoulder, exposing the top of a long zipper than ran almost the full length of her dress. 

Severus reached forward with a shaky hand and pulled the zipper, savoring each new inch of flesh that it exposed. Once it was undone, he helped her out of the dress and marveled at her in her undergarments; this time they were a soft blue. 

"All the way, Sev."

The bra came next. 

"Kiss me," Lily murmured sweetly, letting her bra slide off of her arms and onto the floor. When he complied, she threw her arms back around his neck and returned the kiss deeply. 

Meanwhile, the wizard slid his teacher's lace panties down her hips and let them fall to the floor. She stepped out of them gracefully, then reached back to undo one heel at a time, not breaking their kiss until both shoes were cast aside. The removal of her footwear increased the height difference between them and when Lily pulled away, she looked even smaller in his arms. 

"Now undress yourself, Sev. I want to see all of you." It was amazing how someone so much smaller than him and someone so _naked_ could be running the show. But Severus wasted no time in following his new instruction. 

"I thought you were teaching me to _please_ you," Severus stated dryly as he unbuttoned his shirt the rest of way. He shrugged out of it, exposing his lean, muscled torso, then kicked off his own shoes. He looked down as he undid his belt, his long, dark hair creating a barrier between the two of them. 

"Please look at me, Sev..." But when he did so, Lily gently moved his hands off of his belt and replaced them with her own. She made quick work of the belt, then undid his pants and shoved them down unceremoniously. His boxers came next. 

"What are you doing?"

"You've been following my instructions so far. It seems only fair that you be rewarded."

"But Li--" Severus' breath left him in a quick rush as the witch's fingers wrapped around his cock, finally giving his heated flesh some much needed contact. 

"All _you_ have to do is tell me how much you enjoy it." She winked. Oh God, she _winked._ Seconds later found Lily on her knees in front of him, swirling her tongue around the head of his very thick, very hard erection.


	5. Demonstration

Severus found himself leaning back against the table again, gripping the edges to stop his legs from giving out from underneath him. A deep moan escaped his parted lips and he threw his head back as Lily took him further into her mouth. When he didn't speak, she dug her nails into his thigh as if to say _remember the lesson_. Oh! "Ah, fuck. It's.. it's so good, Lily." Did it please her to hear his feedback? To hear how quickly she could unravel him? His cock throbbed almost painfully between her lips. 

He reached down only to brush a strand of hair from her face and marvel at the sight of her lips around him. It looked to be quite a stretch, but she handled it expertly. When she gently kneaded his balls, he gasped, his eyes fluttering shut again. "Ummm, ugh. Fuck." It took only a few moments for that familiar ache to hit his body again and as his core tightened, he began to panic. "L-Lily... I know you're in charge, but... if you don't stop, I'm.. I'm going to come i-in your mouth."

Without warning, Lily pulled off of his cock, her mouth making a sharp pop! sound as it left him. She stood gracefully, her face flushed and her lips plump and red. "You're right," she told him with a smile, clearly amused at how flustered she'd made him. "It's time for your next lesson. May I use your bed?"

Before he could answer, Lily turned on her heel and led him towards the large bed at the other end of the room. Severus stepped out of his underwear and pants clumsily, his belt clanking to the floor as he did so. What was his next lesson?

"Any good educator knows that some skills are best taught with a demonstration," Lily purred, climbing onto the bed and leaving a naked Severus at the foot of it. 

Oh, hell. Lily Evans was in _his_ bed. 

She gracefully slid onto her back, with her feet at the end of the bed by Severus. One of her hands grasped at her breast, plumping it, rolling the nipple between her slender fingers while the other wandered down her middle towards her sex. "Whatever you see me do with my fingers, I expect you to replicate with your lips, tongue, and hands. Understood?"


	6. Visual Learning

"Understood."

Severus watched in complete amazement as the witch explored her body in front of him. On his bed. Tangled in his sheets. Did she ever do this at home, while thinking of him? He could only hope so. It took everything in him not to let his mouth hang open.

Though Lily Evans was petite, she had curves in all the right places. Her chest and ass were supple, her legs were strong and defined. As her fingers found their way between the folds of her soft, slick cunt, she arched her back and moaned softly. "It'll be even better when you do it," she panted, rubbing her clit in languid circles. Her other hand migrated down from her chest and found its way between her thighs, where she plunged two fingers into her flushed sex. "Mmm, Sev.."

 _"Lily.."_ Without thinking, Severus fisted his achingly hard cock and stroked it while watching her. It felt so good to see her like this, open and wanting him. The way his name sounded rolling off her lustful tongue made him feel like he might explode right then. 

"Show me you've been paying attention," Lily purred, her heavily lidded gaze trailing down the man's body. She removed her fingers and gestured for him to get onto the bed, where she kissed him roughly. Then, she guided him down between her thighs. His response was eager and desperate with need. Wasting no time in flinging her legs over his shoulders, he hurriedly shifted them up the bed, then laid his tongue heavily across her cunt. A free hand reached up to fondle her breast. Despite his excitement, he was deliberate in his actions; he circled his tongue around the bundle of nerves between her thighs, savoring how it made her squirm. And when he plunged two fingers into her, he moaned against her flesh. Fuck, she was so tight and warm. He ground his hips into the mattress in response, wishing he was buried deep inside her again. 

"Yes," Lily hissed, her body tightening around his skillful fingers. "Just like that. Oh, Sev!" She reached down to tangle her fingers in his wild mane, urging him onward as her thighs clenched around his head. "Oh," she breathed, writhing in the sheets. "That's so good, right there, please.. " When her first climax finally tore through her, she trembled and shook, coming hard around Severus' fingers.


	7. Empty

When Severus sat back on the bed, he admired Lily's halo of flaming locks which was wildly splayed from her impassioned thrashing. Her legs continued to tremble slightly as her breathing slowed and Severus ached for her even more as he watched her. Absent-mindedly, he ran his thumb over his bottom lip, then licked it, tasting her on his flesh still. Intoxicating. 

It was Lily's sudden lucid gaze that snapped him out of his daydreaming. "I'm empty without you," she confessed, wrapping her legs around his waist and pulling him forward. 

"What do you mean?" Severus asked curiously, voice low and uncertain. Sure, maybe she meant she just wanted his cock inside of her, but there seemed to be an underlying hint of something else. He followed her touch and leaned forward, propping himself up on his hands on either side of her. "You have me. You've always had me, you know that," the dark-haired wizard reminded her. "No one else," he added, a little sadly. How pathetic was it that he hadn't moved on? As he leaned forward more to kiss her softly, his cock brushed against the tender lips of her cunt. 

But Lily didn't acknowledge his words. Instead, she kissed him back, then murmured against his lips, "Next lesson," before wrapping her legs more tightly around him. It only took a slight flex of her calves to pull him into her and fuck, he fit perfectly.


	8. Final Exams

"Fuck," Severus groaned, pressing his forehead into her shoulder as he adjusted to the feeling of being inside Lily again. _Relax. Don't get carried away._ When he'd finally calmed himself enough not to blow his load immediately, he exhaled deeply. "Okay, I'm ready. Teach me.." 

He propped himself up again and looked down at his partner, whose flushed pink lips were parted and panting. She reached around him and grabbed his ass, pulling him even further into her, then let out of a soft whimper. "Start slow," she breathed. 

When he complied, Lily's emerald eyes fluttered shut and she ran her hands down his back. "Good, Sev. Slow strokes." 

For a moment, Severus thought about wand movements. Like this? he thought, delivering languid thrusts into her, consistently and methodically. He punctuated each stroke with a slightly more forceful thrust as he buried himself in her completely, his balls rhythmically slapping her ass. When he leaned forward to kiss her shoulder, he nipped at the flesh lightly before asking, _"Am I pleasing you, Professor Evans?"_

"Yes," Lily moaned, digging her fingernails into his muscled back. "God, yes, I need more.. _faster."_

Again, he complied. A truly obedient student. But he was shocked when Lily, through panting breaths, looked at him through glossy eyes and said, "Umm, I think I've taught you enough for one day... you may improvise..."

At first, Severus simply slowed his thrusting a little, unsure of what to do with himself. Really? Free reign? Then, as if she weighed nothing, he flipped Lily onto her side while still inside of her, so that he was fucking her with her legs stacked. The increased pressure from her thighs pushing together caused him to doubt himself. He desperately wanted to savour every second with Lily, but fuck, he needed to come. 

As he continued to slam forcefully into the redhead, Severus marveled at every sigh, moan, and whimper he elicited from her. "Ah, fuck," he groaned, tossing his head back and forcing himself to slow down. After a moment at a slower pace, he leaned forward to brush a finger over her lips, then slipped it between them. "Suck," he instructed her, his gaze lustful and serious. His other hand gripped her thigh tightly when she followed his direction and once his finger was wet, he shifted so that he could access her ass while continuing to fuck her. "This is for torturing me at your office," he told her seriously, but he wasn't being malicious or vengeful because he knew that his next move would only curl her toes even more. 

When he slipped his slicked finger between her cheeks, Lily gasped, "Ah! That's... not fair!" she groaned, clenching around the digit. 

"You're close," Severus commented, noting the telltale signs that he'd learned meant an orgasm was approaching. 

"Yes, so close.. I want to come on your cock, Sev."

Once again, he slowed a little, prolonging the process. His finger remaining buried inside her. "Tell me why," he pleaded suddenly. 

"What? Ah, Sev, _please..._ "

"Tell me why you're doing all this. Tell me you miss me. Tell me. I need.. I need to hear it, Lily." He slowed even more, until he was driving into her with agonizingly unhurried thrusts. 

Lily whined in response, but made no attempt to deny him. "I miss you," she choked out. 

The second the words tumbled from her lips, Severus resumed his pace enough to trigger her climax, and he gripped her as she came thunderously around his cock and finger. Then, he withdrew from her ass gently. As she was catching her breath, he slowed, then demanded again, "I need more." Severus' dark mane hung over his shoulders, with wisps of hair plastered to his sweat-slicked face. His cock throbbed inside of her, but he was moving at an almost non-existent pace now. 

"I..." Lily searched for words, her chest still heaving, and reached out to touch the wizard's face despite their awkward angle. "I miss you, Sev.. I miss you every day," she said softly, stroking his jaw. "I told you. I'm empty without you."

"Oh God, Lily.." As if on cue, Severus leaned over to crush his lips to hers as he came, hardly thrusting. His cock throbbed as he spilled himself inside of her, groaning against her lips. It was amazing the effect she had on him and he panted desperately into her mouth as he gave her every last drop of him.


	9. Stay

Before the haze of post-coital bliss could leave them and reality could set it, Severus withdrew from his lover and rolled onto the bed next to her. He stared up at the ceiling as his breathing slowed and blurted out, "Stay with me."

For a moment, there was silence. Then Lily replied, "I can't.. I have to.. work tomorrow." But both of them knew she wasn't talking about work. 

"Cancel," Severus told her simply. "Tell.. your patients you needed to get away for a a while. That you went to see family." He sighed, then choked out the most self-assured thing he'd ever said, likely due to Lily's words during their lovemaking. "It'll be one less night of you missing me. Stay."

It seemed like an eternity, but when Lily finally whispered a soft "okay," Severus smiled and rolled over to kiss her.


End file.
